Researchers Find a Wordle Strategy That Wins 99% of the Time

Researchers at Binghamton University, State University of New York, have developed a mathematical strategy that solved 99% of Wordle puzzles in simulations, using a branch of mathematics called information theory rather than trying to guess the answer as quickly as possible.

In Wordle, players get six attempts to identify a hidden five-letter word, with each guess colored grey, yellow or green to show whether a letter is absent, present but misplaced, or correct. The research team, led by Assistant Professor Congyu "Peter" Wu, applied a concept called Shannon entropy, a way of measuring uncertainty, to look for guesses that would eliminate the greatest number of remaining possibilities rather than guesses that seemed most likely to be the answer.

"A subtle but important insight from the paper is that a guess doesn't have to be the most likely answer; it simply has to be informative," said Donald Stephens, a doctoral student at Binghamton University. By applying Shannon entropy, the objective shifts to maximizing the expected reduction in uncertainty rather than the probability of being right, which can lead to solving the puzzle in fewer guesses.

In simulations, the information theory method solved 99% of Wordle puzzles, compared with 90% for a more conventional strategy centered on frequently used letters such as A, E and R. Using the strategy during a real game would require running a separate script or program: after each guess, the player enters Wordle's color-coded feedback into the program, which calculates the next guess expected to provide the most information.

The work began as a classroom assignment in which Wu challenged students to demonstrate how information theory could be used to solve a real problem, and was later published as a paper, "Solving Wordle Using Information Theory," in the Northeast Journal of Complex Systems.